The present invention relates generally to mattress coverings, such as mattress pads and sheets, and, more particularly, to relatively inexpensive, fitted mattress coverings capable of practical and effective use with mattresses of a standard top surface sizes and a range of heights.
Fitted mattress pads and sheets are commonly available in various forms. The simplest form is one having the top portion and a side skirt formed of the same piece of material and having an elastic strap or cord located around the lowermost periphery of the side skirt to draw the lowermost end of the covering under the mattress and to attempt to retain the covering in-a fitted condition on the mattress. Such coverings have the advantages of ease of manufacture and a consistent appearance with the sides being of the same material as the top. They have the disadvantage, however, of having only a single elastic band along their lowermost periphery to retain an otherwise inelastic covering on mattresses which are being sold more frequently in varying heights, including relatively significant heights of one foot or more. They have a further disadvantage of being expensive to manufacture if the top panel material, which is typically a higher quality textile material such as a quilted material or a higher thread count cotton or cotton blend material, extends down along the sides of the covering sufficiently to cover the sides of mattresses of the greatest heights (thicknesses) currently being sold, so that the coverings can be used with mattresses of a given predetermined top size (e.g. standard, queen, king, etc.) regardless of the mattress height (thickness).
The variation and overall increase in heights of mattresses has led to the introduction of another form of fitted mattress covering, a mattress pad that has a quilted top and a side skirt made of another material. The side skirt is a foot or more in height to cover the sides of all or at least substantially all mattresses being sold and is elasticized over its entire height. In addition, a heavier elastic band or cord is also attached to the lowermost periphery of the skirt as with the original coverings. Such pads have been made with skirts formed by joining with a conventional, inelastic textile material layer, a layer of a special, non-woven, elastic sheet material. Such pads have also been made with side skirts formed from a single layer of inelastic material, which is elasticized by being stitched with multiple (e.g. six or more) uniformly spaced parallel rows of elastic threads sewn into the otherwise inelastic, single skirt material layer. Such pads have also been made using side skirt material which is itself knitted or woven from elastic thread.
All three forms of skirt construction offer elasticity over the full height of the skirt. It has been found that providing elasticity over the full height of the skirt provides a neat, gathered appearance and improves mattress cover retention due to the ability of the elasticized material to grip the side walls of the mattress in addition to any gripping provided by the elastic cord around the lowermost periphery of the skirt.
It has further been found that an acceptable degree of fit and retention of mattress pads can be achieved if some of the length of the side skirt of the mattress pad extending from the top is provided by a band of inelastic material closely fitted to the sides of the mattress. This band can be provided by supplying a one-piece, rectangular top portion with four rectangular panels extending from the edges of the top portion. The panels are turned transversely to the top portion and seamed together forming an upper portion of the side skirt. A second band of elasticized inelastic material is attached to the lower periphery of the upper skirt portion to complete the skirt. The lower band is elasticized as noted above by bonding to a band of inelastic fabric, a layer of a non-woven, elastomeric material coextensive with the band, or by stitching several rows of elastic thread into the band or by providing a band knitted or woven from elastic threads. Again, a heavier elastic cord is attached to the lower most periphery of the second band as with the other mattress coverings. It has been found that an upper skirt portion seamed at four corners so as to provide a closed loop of inelastic material extending generally perpendicularly to the top portion of the pad and closely fitting around a mattress on which the pad is mounted, combined with the relatively lighter elastic grip of the lower band of elasticized material and traditionally heavier elastic cord around the bottom of the skirt, also provided a sufficient grip along the height of the skirt for such covers to remain in place when used with mattress of varying heights.
While there are other differences among these mattress coverings, at least one factor which is significant in distinguishing these constructions from one another is their cost of manufacture. This factor is becoming ever more important as a significant portion of the commercial market for these coverings is controlled primarily if not exclusively by price. Thus, the least expensive construction of such covers which still provides an appearance and gripping performance acceptable to distributors and consumers, is very valuable.